<!DOCTYPE html>
    <html lang="en" style="width: 100%;height: 100%">
    <head>
        <meta charset="UTF-8">
        <title>Demo</title>
    </head>
    <body style="width: 100%;height: 100%">
      <div id="root" style="width: 100%;height: 100%"></div>
        <script src="bundle.js"></script>
    </body>
    </html>